Techni-Blog: To Help You Better Understand Bathroom Toilet Partition Installations

Designing the Perfect Toilet Partition Repair Bracket October 10 2014

It took several years of measuring public restroom toilet stalls before I decided it was possible to design a replacement partition bracket that did not tear out of the wall as so many do. In this age of bathroom toe tapping to attract sexual favors, one can imagine how awkward it would be to get caught peering over a stall divider with a pair of calipers in hand. Luckily, during my several years of casual public restroom measurements, I never had the authorities called on me for suspected deviant behavior.

There are around 100 million public restroom stalls in the United States alone. I measured and documented 109 sets of wall bracket dimensions, partition thicknesses, and failure modes to understand the problem before designing a repair bracket. This sample size may be small compared to the 100 million commercial toilet stalls out there, but it is sufficient enough to bound the problem.

The Toilet Partition Wall Bracket Problem

I do not know how many people notice the staggering number partition brackets that have torn out the wall such as the one shown in Figure 1. The results of my study indicate that 25 percent of brackets have failed wall anchor attachments. The partition design using these standard brackets has been around for a long time, and only recently have full-length extrusions started replacing them in new installations. Using this logic, that puts the number of partitions that have failed wall attachments at around 25 million in the US.

Standard Failed Partition Wall Bracket

Figure 1: Failed toilet partition wall bracket.

In this article, I will not get into the physics of explaining why these bracket attachments are failing. Please read Why Bathroom Toilet Partition Wall Brackets Come Loose if you would like a better understanding.

A summary of the design problem is that a vertical shear load is being applied to the wall brackets when they were only designed to carry a compression load. As a partition rests against the wall, these brackets were supposed to support it. All the weight (vertical load) of the partition was to be carried by the pilaster alone. The root cause of the problem is that in order to balance the load as described, the pilaster floor bracket has to be secure, not slipping along the floor. Unfortunately, this design worked on paper but does not translate into the real world. The pilaster, in fact, does slip and the wall brackets carry vertical load, which they were not designed to take. This vertical load pries the fastener anchor out of the wall.

The Cost Effective Solution to Eliminating Partition Wall Attachment Failures

The easiest and most cost effective repair of the bathroom toilet partition wall attachment is to design a bracket that can handle a portion of the partition’s weight. Therefore, each wall bracket will need to handle a maximum ¼ the weight of the divider panel, conservatively assuming the pilaster floor attachment is free to slide. When a vertical load is applied to a standard bracket that contains only one row of partition fasteners, there is an eccentricity that rotates the bracket around the lower wall contact and puts the wall fasteners in tension as shown in Figure 2.

Load balance for a standard wall bracket under vertical shear

Figure 2: Load balance for a standard wall bracket under vertical shear.

Rather than try to balance this eccentric load by putting the wall fasteners in tension, it is a much better design to add another fastener common-to the partition. Partitions are made from steel, wood, and dense plastic that is much stronger that drywall.

So, the replacement bracket uses two fasteners to carry the eccentricity into the partition by efficiently bearing the load. Figure 3 shows the new, improved load balance.

Improved load balance using the new bracket design

Figure 3: Improved load balance using the new bracket design.

Any good modular replacement bracket will need to use the original fastener locations for a clean, professional repair. This will require a slot to align with the original partition hole because of the varying locations used by the original bracket manufactures. But, what is the correct location and size of the slot? We will use the empirical data from the bathroom measurements.

Distance from panel fastener center to wall

Figure 4: Distance from panel fastener center to wall.

From the data presented in Figure 4, one can see the relatively narrow range of hole locations. The newly designed bracket encompasses this range along with some extra for tolerances. Also, notice in Figure 3, there is a small dimple on each side of the slot. Both sides of the bracket have dimples at opposite locations. There are a couple non-standard brackets being produced, one is extra long and one extra short. These are very unusual and I did not find any instance of their use during my survey of public bathrooms. However, in case someone needs to replace one of these non-standard length brackets, the dimples are there to start the drill in the proper place as to match the original bracket holes.

Base of replacement bracket

Figure 5: Base of replacement bracket.

The next step is to design the base of the bracket to pick up the original wall fastener locations while keeping the partition in the same place. A slot is one method; however, the bracket should not slip across the wall if the fasteners are loose. Figure 5 shows a design that solves this problem.

Figure 6, below, depicts measurements taken of wall fastener spacing on original two-eared brackets. The slot and hole geometry in the new design accommodates these measured distances. Data is missing for the first 26 measurements.

Wall fasteners spacing

Figure 6: Wall fasteners spacing survey.

Another variable of the new bracket is the panel thickness it will need to accommodate. Figure 7, below, shows the range of panel thicknesses used in today’s restrooms. The most popular size partition is the 1-inch thick panel. Although the actual exact thicknesses of the panels vary, they are all less than 1.05 inches. The least thick of the surveyed partitions was ½ inch. These are rare, however, as can be seen from the data in Figure 7. Shims will be added to the replacement kit to accommodate any partition thickness from ½ to 1 inch thick.

Panel thicknesses of the surveyed partitions

Figure 7: Panel thicknesses of the surveyed partitions.

Flange thicknesses were sized to ensure the proper surface contact stresses under the most extreme loads. These new brackets have an abundance of strength to handle real-world abuses.

Final Design of the Replacement Toilet Partition Wall Bracket

The manufacturing method of the replacement toilet partition bracket should depend on how many could be sold. With an estimated demand of around 25 million toilet stalls that need to be repaired, the method should be scalable. It was decided to start with sections of aluminum extrusions and CNC machine features to precise tolerances. An anodized coating is then used to ensure a trouble-free, durable surface. The final bracket design is shown in Figure 8.

Final design configuration of the toilet partition wall bracket

Figure 8: Final design configuration of the toilet partition wall bracket.

In order for the bracket to function as designed, proper hardware is packaged with each kit. All fasteners and wall anchors are one size larger than those used to install standard partitions, ensuring a snug fit. Each kit contains 2 brackets and all the hardware needed to repair one partition panel. The kit is shown in Figure 9.

Figure 9: Fix-a-Stall bathroom partition repair kit with hardware.

These kits are available in three colors, Satin Silver, Titanium Gray or Ebony. They can be purchase at the Fix-a-Stall website or at Amazon. Installation instructions are include or available online in either written of video format..


Why Bathroom Toilet Partition Wall Brackets Come Loose April 23 2014

After many years of noticing bathroom partition brackets pulling out of the walls, I decided to sit down and understand exactly what was happening. Luckily, my profession is to perform aerospace structural analysis so I was equipped to apply engineering principles this problem. My findings are shown below, using words to describe loads rather than numbers for simplicity.

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Figure 1: Original Partition Wall Bracket with Single Row of Fasteners.

The image shown in Figure 1, above, is of a toilet partition bracket coming loose from the wall. This can be seen in commercial restrooms all over the United States. Actually, my survey showed 25% of partitions mounted to wall with this style bracket are coming loose. It is no surprise that the current trend of partition installations has gone toward full-length extrusions along the wall. That is fine for new installations, but what do we do with the older ones using brackets like the one show in the figure? One solution is to replace these with two-fastener-row brackets. The Fix-a-Stall Bracket Kit upgrades any partition wall mount. Its modular design picks up the original fastener hole locations for a professional repair. All the holes diameters’ are enlarged one size from the original installation to ensure a snug fit. Then, a second fastener is added common-to the partition for a trouble-free attachment.

Figure 2: Fix-a-Stall Bracket over a Standard (single-fastener-row) Wall Bracket.

To understand why the partition brackets pull fasteners from the wall, it is necessary to mentally stand back and look at the whole installation. Essentially, the partition was meant to lean against the wall and the wall brackets were meant to just support compression loads. The vertical load from the partition’s weight was to be supported by the pilaster, in theory. Refer to Figure 3. Red arrows represent loads needed to hold the assembly in place.

Figure 3: Theoretical Partition Support Loads.

The wall brackets could act as compression links with no loads going into the fasteners common-to the wall. For this load balance to happen, any lateral load supported by the wall would have to be opposed by the pilaster floor attachment. This could be a great design, since no appreciable loads gets applied to the fasteners holding the brackets to the wall. The partition applies no shear load to the wall fasteners, so this design seems to have great advantages.

Unfortunately, the pilaster has some flexibility and the floor brackets have their own design limitations, so the whole partition assembly tends to slip over time. The actually load balance of the partition installation is closer to that shown in Figure 4, below.

Figure 4: Actual Partition Support Loads.

As the pilaster bends and the floor bracket slips, the load has to be balanced another way as shown in the figure. Unfortunately, this balance requires a small vertical load at each wall bracket (approximately ¼ the partition weight). If we look at just the wall bracket, it will become obvious why fasteners get pulled from the wall. Refer to Figure 5, below.

Figure 5: Original Partition Wall Bracket Loads.

Even with a fraction of the partition weight carried by the wall bracket, this translates into high fastener tension. The only way the bracket can keep from rotating is by putting the wall fasteners/anchors in tension. Since anchor pull-out strength in drywall this is the weakest part of the entire partition assembly, the anchors eventually pull from the wall and the bracket rotates to a position show in Figure 1.

A solution to this problem is to add another fastener in the bracket to carry the eccentric load. Since standard wall brackets vary in height from each manufacturer, a slot is used to pick up the original fastener locations. The second fastener is match drilled to the bracket for a perfect fit. Now the wall anchors only need to take shear loads, as shown in Figure 6 below.

Figure 6: Fix-a-Stall Wall Bracket Loads.

The Fix-a-Stall Wall Bracket also has a modular base that can accept hole locations in the wall used by any standard bracket (Figure 7, below).

Figure 7: Base of Fix-a-Stall Partition Wall Bracket Showing Modular Design (shown in Titanium Gray).

The original wall anchors are removed, the holes are enlarged to 5/16 inch, and new anchors are installed. Then, the closest of the three holes (Figure 7, left side) is used to attach the bracket to the wall. The other fastener is installed through the slot on the other side of the bracket (Figure 7, right side). This design keeps the bracket from sliding on the wall, even with loose fasteners.

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Figure 8: Fix-a-Stall Partition Wall Bracket (show in Satin Silver).

I hope this article spreads new light onto the load paths of a partition installation. If you are installing new partitions using the standard wall brackets, you shown now recognize how important it is to secure the pilaster floor brackets properly. This will create load paths closer to those shown in Figure 3 and minimize the fastener prying.

If you have brackets that look like the one in Figure 1, and are trying to repair them as cost effectively as possible, while maintaining a professional look, the Fix-a-Stall Partition Repair Kit is a perfect choice. The finished installation is shown below (Figure 9).

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Figure 9: Fix-a-Stall Wall Bracket Kit - Installed.

The brackets kits are available in 3 colors, Silver Satin, Titanium Gray or Ebony (black). Each kit comes with two brackets and all the hardware needed to repair one partition.

Figure 10: Fix-a-Stall Partition Repair Kit.

For more information, check out the Fix-a-Stall Partition Bracket Website Page.